IMMUNE-RESPONSE OF STRESSED RATS TREATED WITH DRUGS AFFECTING SEROTONINERGIC AND ADRENERGIC TRANSMISSION

Stressful conditions interfetes with immune raspone. One of the principal mechanisms is activation of hypotnalamo-pituitary-suprarenal axis by central serotoninergic and adrenergic pathways. Alternative mechanisms bypassing the axis also take part in stress-induced immunomodulation. Immuinosuppression caused by repeated restraints or overcrowding was usually accompanied by increased metabolism of serotonin in the brain (as indicated by increased level of its metabolite, 5-HIAA) and by increased levels of corticosterone in plasma. Changes in lymphatic tissues of stressed animals that result in suppression of immune response apparently "outlive" fluctuating changes in neurotransmitter and corticosterone levels. Drugs that alter serotoninergic or adrenergic transmission interfere with tamunosuppressive effect of stress either synergistically (augmenting suppression) or antagonistically (preventing it). Since immunocornpetent cells possess serotoninergic and adreneigie receptors, such drags may exert their effect either via central neuroendocrine mechanisms, or by direct effects on immunocompetent cells. © 1990.